Incandescent electric lamp



(No Model.)

W. MAIN.

INGANDBSOENT ELECTRIC LAMP.

No. 336,729. liyz Patented Feb. 23, 188-6.-

IINVENTOR ATTORNEYS kWiTNESSES:

N, PETERS, PhnlwLlthogrzNl-r, Wilhlnginn. D. (L

UNITED STATES PATENT OFFICE.

IVILLIAM MAIN, OF BROOKLYN, NEW YORK.

ENCANDESCENT ELECTRlC LAMP.

SPECIFICATION forming part of Letters Patent No. 336,729, dated February 23, 1886.

Application filed July 30, 1855. Serial No. 173,010. (Xo model.)

To all whom it may concern:

Be it known that 1, WILLIAM. llIAIN, a citizen of the United States, residingin Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Incandescent Electric Lamps, of which the following is adesoription in such full, clear, concise, and exact terms as to enable any one skilled in the art or arts to which my invention belongs to make and use the same, reference being had to the accompanying drawings, making part of this specification, and to the letters and figures of reference marked thereon.

My invention consists of a novel form of incandescenteleetric lamp having a metal base, and the means for illuminating; and extinguishing the same.

Reference being had to the d 'awings making part of this specification, Figure l is a longitudinal cross-section through my improved lamp. Fig. 2 is an elevation of the lamp switch,by means of which the current is turned in and out of the lamp, for the purpose of illuminating and extinguishing the same. Figs. 8 and at are top and bottom views of detail parts of said switch. Fig. 5 is a top view of a sectiontl'irough the lamp on the dotted line 009 Fig.1; and Fig.6 illustrates one means of exhausting the lam p-chamber.

I take a cylindrical piece of metal, a, formed as shown in the drawings, and on the lower side of the perforated partition in said cylinder I place the insulatingring f. The flanged metal tube Z) is then slipped in place, and held in position, if desirable, by the perforated cap 0. The upper-end of the pipe I) is screw threaded to receive the metal nut d, which has inclined sides to correspond with the sides of the cavity in the top of the cylindrical piece a. Before the nut (Z is screwed on the tube b a disk of suitable insulating material is placed between the said nut and its seat in the cylindrical piece a. These disks 0 and f may be made of mica, although I do not confine myself to the use of this single material. The interstices between the nut d, cylindrical piece a, pipe I), and ring 0 are filled with any suitable insulating and sealing material before the nut is screwed down home.

It will be observed that the hole in the partition of the cylindrical piece a islarge enough to allow the pipe 12 to pass through without touching, and that the tapering nut d centers the pipe b, so that it does not come in contact with the cylindrical piece a or the flanged ring 0, and is completely insulated therefrom.

In connection with the disks 0 and f, for the purpose of insulating and hermcticallysealing the said parts, I prefer to use a plasticeement, which is set either by chemical action or by the assistance of heat. The nut d is screwed home while this insulating and sealing material is in a plastic state, thereby packing it tightly in all the said interstices and squeezing out the surplus material. The ring 0 may or may not be employed; but I prefer to use it. After the insulating material has been intro duced and the nut screwed home I invert the whole and pour insulating and sealing material around the flange on the pipe I), and then screw down the flanged ring a, removing any surplus material that is squeezed out about the pipe 0. The standards supporting the illuminating-conductor of the lamp are then inserted, respectively,in the cylindrical piece T a and the nut d, and are preferably formed of stiff wirej j, to which the illuminatingfilament may be directly attached, or by means of interl'nediate platinum wires, 7t 7t. I next prepare a spnirmetal cup 9 snbstantially of the form shown in the drawings, which snugly fits the cylindrical piece a, and which in its outer fold embraces the lower end of the glass illuminating-chambcr of the lamp hermetically sealed therein. By forming the spun-metal cup as shown a free circulation of airis admitted to both sides of that portion of the said cup which contains the bottom of the glass chamberi 1', thereby tending to keep the same cool and preserve the joint air-tight. Again, any heat conducted to the base a b c d, before reaching said 'oint,is made to pass over a considerable radiatingsurface and is thus diminished. This form of cup also forms an elastic support for the glass chamber i i, which considerably diminishes the liability of said chamber to crack or tear away from the sealing material in which it is bedded.

To exhaust the lamp-chamber, asoft-metal pipe, 72, Fig. 6, is soldered into the lower end of the pipe I), which pipe 72 is connected to any suitable exhaust pump. This pipe may be made of lead or other suitable material, so that when the chamber has been cxhausted the pipe may be pinched and worked together to completely close the bore thereof, and then cut off and formed into a small projecting teat. (See Fig. 1.) As an extra precaution against leakage, solder may also be applied.

The switch by means of which the electrical current is turned in and out of the lamp is formed as follows: A base, m, made of insulating materialsuch as gutta percha or wood is fitted with the binding-posts n a, one of which is electrically connected with the rod 1, spring a, and contact-rod 1', said contactrod r playing longitudinally in the bore of the cylinder m. (See Fig. 1.) The bindingpost a is electrically connected to the incline plates q q g by means of the wires 0. The cylinder m, Fig. 2, is provided with a series of short inclines, p qp g, &c., the inclines g being faced with metal and electrically connected to the binding-post n, and the inclines 1) being formed from the insulating material composing the said cylinder. Revolving on a shoulder above the said inclinesis the metal disk 2, provided with the flat metal springs t t, which ride up and down the inclines when the disk is turned with a righthand revolution about its axis. A metal flange-ring, 1), screws down upon the disk 2, which holds the disk in place, but does not interfere with its revolution. This metal flanged-jug has also an external screw'thread, by means of which it is screwed in the lower end of the cylindrical piece, a, the teat formed on the end of the tube b forming electrical connection with the spring-rod 1-, as shown in Fig. 1 ofthe drawings. It is obvious that by the revolution of the disk .2, the circumference of which should be suitably milled, the current is turned in and out of the lamp as the springs t make contact alternately with the inclines 1) p p and q q 1., My purpose of employing more than one incline q is to diminish the sparking at these contacts, and also by providing more than one path for the current to guard against a failure in operation if a good contact should not be made at either of said points.

The form of switch which I have here described is more compact and simple than any other cflicient switch of which I have any knowledge. Instead of making the disk holding the springs the revolving part of the switch, I may, of course, make this stationary, and the part containing the inclines adapted to revolve.

The course of the current through the lamp is, therefore, as follows: From the generator to bindingpost n, conductor 0, inclines q, springs 15, disk .2, ring 2;, cylindrical piece a,

supportj, illuminatingconductor, support j, nut d, tube b, spring-rod 1- u r, binding-post it, back to generator.

lVhen it is desired to LlDSGtLlllllGliLlll1)-Cll2tl]lher to replace the illuminating-conductor, or for any other purpose, heat may be applied to the lower rim of the spun cup melting the solder, and permitting the cup to be removed from the base without interfering with the sealing contained therein.

To re exhaust the lamp-chamber after the lastnientioned joint has been scaled, the projecting teat and plug may be withdrawn from the end of the tube 1), and pipe leading from the exhaust-pump inserted, and the lamp ex hausted and sealed, as hereinbet'ore described.

Having described my invention, I claim and desire to secure by Letters Patent- 1. In an incandescent electric lamp, a re volving disk set upon the axis of the lamp and intervening between the bottom of the lamp and the holder thereof, said disk being provided with suitable contacts and insnlating section coaeting in the circuit, said disk rotating independently of the lamp and the holder thereof, by which the current is turned in or out of the lamp by the rotation of said disk about its own axis and the axis of the lamp, substantially as described.

2. In an incandescent electriclamp, a switch for turning the currentin and out of the lampcircuit, consisting of a disk set upon the axis of the lamp and made to rotate continually in one direction about its own axis and the axis of the lamp, the lamp and bolder remaining stationary, said disk being fitted with the necessary contact and insulating points or sec tions, substantially as described.

3. In an incandescent electric lamp and form ing theillun'iiuating-chamber thereof, the combination of a transparent globe and a metal base consisting of a double convoluted cup,one of which convolutions supports the illuminating-chamber, and the other furnishes an air and radiating chamber around the base of the lamp, substantially as described.

4:. A metal base to support the glass chamber of an incandescent electric lamp, consisting of atubesection havingadouble eonvolute spun about it, permitting the metal walls that embrace each side of the glass chamber to eX- pand independently of said tube, substantially as described.

5. A metal base of theilluurinating-chamber of an incandescent electric lamp, consisting of the combination of a cup, g, cylindrical piece a, flanged pipeb. and nut d, all being connected and combined substantially as described.

6. An electric switch consisting ofthecombination of a spring contact-rod, r u r, connected with one binding-post, anda revolving metallic disk, 2, provided with metal springs t, and a series of inclines, p q, suitably provided with contacts connected with the other binding-post, substantially as described.

\VILLIAM MAIN.

lVitnesses:

WM. H. BROADNAX, J. EDGAR BULL. 

